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Kraft, Michael. "Closed loop digital accelerometer employing oversampling conversion." Thesis, Coventry University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361662.
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Kallem, Devi Shravanthi. "Design of a patient monitoring system using 3D accelerometer sensors." Manhattan, Kan. : Kansas State University, 2010. http://hdl.handle.net/2097/4132.
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Aiello, Christina Jane. "Investigating Gyroscope Sway Features, Normalization, and Personalization in Detecting Intoxication in Smartphone Users." Digital WPI, 2016. https://digitalcommons.wpi.edu/etd-theses/388.
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Alcohol abuse is the third leading lifestyle-related cause of death for individuals in the United States, causing 88,000 deaths each year in the United States from 2006-2010. Existing smartphone applications allow users to manually record their alcohol consumption or take cognitive tests to estimate intoxication levels; however, no smartphone application passively determines one's level of intoxication. After gathering smartphone sensor data from 34 "intoxicated" subjects, we generated time and frequency domain features such as sway area (gyroscope) and cadence (accelerometer), which were then classified using a supervised machine learning framework. Other novel contributions explored include feature normalization to account for differences in walking styles and automatic outlier elimination to reduce the effect of accidental falls by identifying and removing the top and bottom of a chosen percentage of the data. Various machine learning classifier types such as Random Forest and Bayes Net were compared, and J48 classifier was the most accurate, classifying user gait patterns into BAC ranges of [0.00-0.08), [0.08-0.15), [0.15-0.25), [0.25+) with an accuracy of 89.45%. This best performing classifier was used to build an intelligent smartphone app that will detect the user's intoxication level in real time.
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Grassham, Paul J. "The design and application of polymeric materials in a novel light modulated accelerometer." Thesis, Sheffield Hallam University, 1992. http://shura.shu.ac.uk/19712/.
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A novel accelerometer based on light modulation has been designed and a prototype device manufactured. The device utilises the change in refractive index brought about by stress induced by the applied vibration. A detailed mathematical analysis of several feasible sensing designs has been performed to aid the design process. A mathematical model has been developed to assess the performance characteristics of the light modulated accelerometer the results of which were also used as a design tool. The prototype accelerometer was tested, from 1 g to 50 g between frequencies of 25 Hz to 2000 Hz, on a vibration system under three modulation schemes. The acceleration response of the device was seen to be linear over the testing range whilst the frequency response dropped off initially and levelled off at approximately 1 kHz. An experimental accelerometer was also assembled on the vibration table so that various materials could easily be tested without having to undergo precise machining. The acceleration and frequency responses showed similar behaviour to those obtained with the prototype accelerometer. However, the actual response levels varied with each material. To aid in the development of the accelerometer the stress-optic and thermo-optic coefficients have been determined for a range of polymeric materials. The stress optic coefficient was determined for polycarbonate, polymethyl methacrylate, polvinyl chloride and araldite epoxy resin using a circular polariscope and two interferometer configurations up to the yield stress of the materials tested. Each material showed a constant coefficient over the testing range. The results obtained using each technique were in good agreement with each other and the limited literature data available. The thermal variation of refractive index was also determined for the same materials. The Abbe refractometer was used for the determination between 5 and 140°C using five wavelength sources and two interferometer configurations using a HeNe laser from -50°C to approximately 30° above the glass transition temperatures. The change in index was found to be linear over the temperature range tested. However, at the glass transition temperature a change in gradient was observed with each material. Two simple mathematical relationships were used to predict the thermo-optic coefficient. These gave values reasonably close to those obtained in experiment.
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Maddala, Sasanka, and Veerababu Velugubantla. "Development of a Multi Sensor Android Application." Thesis, Blekinge Tekniska Högskola, Institutionen för matematik och naturvetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-20862.
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There has been an enormous growth in the usage of smartphones in recent times. Smartphones are not limited to communication purposes. It has various applications designed as per the daily requirements of humans such as web-searching, online shopping, bank transactions, games, etc. With the increase in the usage of the smartphone, the more useful information is captured and stored by it, which raises the question of security. The goal of this research is to develop two android applications. One is a sensor detector application and the second is a screen lock application. The first application will help the user to identify all the hidden sensors and working sensors on the mobile phone. This application even describes the features and usage of every sensor in detail. Using a graphical description of each sensor which depicts the behaviour of each sensor as per environment/movement. The second application is designed using a combination of two sensors. Screen lock applications contain two main factors. One is to work properly in all cases and efficiently do the functions that are required to do. The second is to maintain a smooth inner system interaction because in addition to locking the screen this application should make sure to hide the display of all the other applications without closing the process of these applications. With the increase in the usage of the smartphone, it becomes difficult for older generations to memorize the security pattern techniques and use them. This thesis develops a simple technique in the mobile authentication android application. The thesis is developed on the Android studio platform. The background functionality of the app is coded in java using android SDK tool and frontend of the application is designed using XML files. The GENYMOTION emulator and a mobile phone are used to test the output.
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Kumar, Mithilesh. "A Motion Graph Approach for Interactive 3D Animation using Low-cost Sensors." Thesis, Virginia Tech, 2008. http://hdl.handle.net/10919/34168.
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Interactive 3D animation of human figures is very common in video games, animation studios and virtual environments. However, it is difficult to produce full body animation that looks realistic enough to be comparable to studio quality human motion data. The commercial motion capture systems are expensive and not suitable for capture in everyday environments. Real-time requirements tend to reduce quality of animation. We present a motion graph based framework to produce high quality motion sequences in real-time using a set of inertial sensor based controllers. The user's action generates signals from the controllers that provide constraints to select appropriate sequence of motions from a structured database of human motions, namely \emph{motion graph}. Our local search algorithm utilizes noise prone and rapidly varying input sensor signals for querying a large database in real-time. The ability to waive the controllers for producing high quality animation provides a simple 3D user interface that is intuitive to use. The proposed framework is low cost and easy to setup.<br>Master of Science
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Froyuk, K. V., V. M. Luzhbin, S. G. Yehorov, К. В. Фроюк, В. М. Лужбін, and С. Г. Єгоров. "Sensors for determining the spatial position of the aircraft." Thesis, National aviation university, 2021. https://er.nau.edu.ua/handle/NAU/50500.
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1. Kharchenko V.P., Ostroumov I.V., Avionics. Textbook. - K: NAU, 2013 (in Urkainian)
2. Andrusevich A.O., Kasyan V.S., Stadnik V.V. Information and measuring devices, avionics systems and complexes. Textbook. - Kryvyi Rih, 2011 (in Urkainian)<br>The aviation community must constantly work to improve safety around the world. The work of modern aviation is the need to obtain in real-time the spatial position of aviation systems during the primary and secondary training of operators to operate the above systems. This will not only obtain the characteristics of each operator and identify the patterns of its activities, but also further predict the occurrence of systematic errors inherent in a particular operator.<br>Авіаційна спільнота повинна постійно працювати над підвищенням безпеки у всьому світі. Робота сучасної авіації полягає у необхідності отримання в реальному часі просторового положення авіаційних систем під час первинної та середньої підготовки операторів з експлуатації вищезазначених систем. Це дозволить не тільки отримати характеристики кожного оператора та виявити закономірності його діяльності, але й надалі передбачити появу систематичних помилок, властивих певному оператору.
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Singh, Mahendra, Stuart McNamee, and Allen Khosrowabadi. "MODULAR AFFORDABLE GPS/INS (MAGI)." International Foundation for Telemetering, 1999. http://hdl.handle.net/10150/607342.
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International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada<br>The GPS/INS equipment is used at the Air Force Flight Test Center (AFFTC) to collect
time space position information (TSPI) during testing. The GPS-based test
instrumentation is lagging behind available commercial technologies. Advancing
technologies for test use requires investigation of affordable commercial equipment. To
enable technology insertion for state of the art testing, there is a need for more robust,
flexible, reliable, modular, affordable low cost TSPI systems capable of operating in all
flight environments. Modular (plug-and-play) hardware and software, quick and easy to
re-configure, are required for supporting various test platforms from fighter aircraft to
cargo size aircraft. Flight testing dynamics are such that, GPS-only systems tend to lose
data during critical maneuvers. To minimize this data loss, inertial measurement systems
coupled with GPS sensors are used in most sophisticated range instrumentation packages.
However, these packages have required fairly expensive inertial units, are usually very
large and not very flexible in terms of quick and easy reconfiguration to meet the unique
needs of AFFTC’s test customers. WADDAN SYSTEMS has begun to address this
problem with a modular design concept, which incorporates their high-performance
navigation quality inertial measurement unit, but with costs comparative to that of lower-end
performance inertial units. This paper describes WADDAN’s concept and the
components that make up MAGI; and addresses some of the preliminary testing and near-term
proposed activities. In general, the system will provide GPS, inertial and discrete
MIL-STD 1553, RS-232/422 and video data from the participant. The MAGI will be
structured around the Compact personal computer interface (PCI) backplane bus with on-board
recording and processing and will include real-time command and control through
a UHF data link.
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Yenuganti, Nagalaxmi. "Authentication in Wireless Body Area Networks (WBAN)." Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6442.
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With the advancements in technology and computing environment capabilities, the number of devices that people carry has increased exponentially. This increase initially occurred as a result of necessity to monitor the human body condition due to chronic diseases, heart problems etc. Later, individuals’ interest was drawn towards self-monitoring their physiology and health care. This is achieved by implanting various sensors that can proactively monitor the human body based on medical necessity and the health condition of the user. Sensors connected on a human body perceive phenomena such as locomotion or heartbeat, and act accordingly to form a Body Area Network. The primary concern of these sensors is to ensure a secure way of communication and coordination among the devices to form a flawless system. A secondary concern is wireless sensor authentication, which ensures trustworthiness and reliable gathering of a user’s data. To address this concern, we designed a secure approach using low cost accelerometers to authenticate sensors in Body Area Networks.
To ensure authentication in on-body sensor networks, we need a mechanism which intuitively proves all the communicating nodes are trusted ones. In order to achieve sensor authentication, we used accelerometer data gathered from sensors to distinguish whether or not the devices are carried on waist of same individual’s body. Our approach is focused at analyzing walking patterns recorded from smartphone accelerometers placed in the same location of the user’s body, and we present results showing these sensors record similar pattern.
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Ahmed, Qutub Uddin, and Saifullah Bin Mujib. "Context Aware Reminder System : Activity Recognition Using Smartphone Accelerometer and Gyroscope Sensors Supporting Context-Based Reminder Systems." Thesis, Blekinge Tekniska Högskola, Institutionen för datalogi och datorsystemteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-4122.
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Context. Reminder system offers flexibility in daily life activities and assists to be independent. The reminder system not only helps reminding daily life activities, but also serves to a great extent for the people who deal with health care issues. For example, a health supervisor who monitors people with different health related problems like people with disabilities or mild dementia. Traditional reminders which are based on a set of defined activities are not enough to address the necessity in a wider context. To make the reminder more flexible, the user’s current activities or contexts are needed to be considered. To recognize user’s current activity, different types of sensors can be used. These sensors are available in Smartphone which can assist in building a more contextual reminder system. Objectives. To make a reminder context based, it is important to identify the context and also user’s activities are needed to be recognized in a particular moment. Keeping this notion in mind, this research aims to understand the relevant context and activities, identify an effective way to recognize user’s three different activities (drinking, walking and jogging) using Smartphone sensors (accelerometer and gyroscope) and propose a model to use the properties of the identification of the activity recognition. Methods. This research combined a survey and interview with an exploratory Smartphone sensor experiment to recognize user’s activity. An online survey was conducted with 29 participants and interviews were held in cooperation with the Karlskrona Municipality. Four elderly people participated in the interview. For the experiment, three different user activity data were collected using Smartphone sensors and analyzed to identify the pattern for different activities. Moreover, a model is proposed to exploit the properties of the activity pattern. The performance of the proposed model was evaluated using machine learning tool, WEKA. Results. Survey and interviews helped to understand the important activities of daily living which can be considered to design the reminder system, how and when it should be used. For instance, most of the participants in the survey are used to using some sort of reminder system, most of them use a Smartphone, and one of the most important tasks they forget is to take their medicine. These findings helped in experiment. However, from the experiment, different patterns have been observed for three different activities. For walking and jogging, the pattern is discrete. On the other hand, for drinking activity, the pattern is complex and sometimes can overlap with other activities or can get noisy. Conclusions. Survey, interviews and the background study provided a set of evidences fostering reminder system based on users’ activity is essential in daily life. A large number of Smartphone users promoted this research to select a Smartphone based on sensors to identify users’ activity which aims to develop an activity based reminder system. The study was to identify the data pattern by applying some simple mathematical calculations in recorded Smartphone sensors (accelerometer and gyroscope) data. The approach evaluated with 99% accuracy in the experimental data. However, the study concluded by proposing a model to use the properties of the identification of the activities and developing a prototype of a reminder system. This study performed preliminary tests on the model, but there is a need for further empirical validation and verification of the model.<br>+46707560843
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Mylonas, Christos, and Samir Đulić. "Smarttelefon-sensorernas möjligheter - En studie om barometer-, GPS- och accelerometersensorer. The smartphone sensor possibilities - A case study featuring the barometer, GPS and accelerometer sensors." Thesis, Malmö högskola, Fakulteten för kultur och samhälle (KS), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-20469.
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Denna rapport sammanfattar resultat av ett examensarbete på en högskoleingenjörsutbildningsom utfördes av två studenter på Malmö högskola.Arbetets syfte var att genomföra en mängd olika experiment med accelerometer, barometeroch GPS i en modern smarttelefon. Ett antal scenarier för en tänkbar sensoranvändning i applikationerformulerades för att vägleda olika experiment. Experimentdata dokumenterades noggrantoch analyserades med avsikten att skapa en databank med information för framtida studier.Analys av data inkluderar höjdbestämning i naturen och i byggnader med hjälp av barometersensor,geografisk position med hjälp av GPS, hastighet och acceleration under en hissfärdmed hjälp av accelerometer.Rapporten innehåller en omfattande litteraturstudie om användning av sensorer vid inomhuspositionering.Från analys av mätdata, kom vi fram till slutsatsen att är möjligt att beräkna höjdenfrån barometerdata med bra noggrannhet under optimala omständigheter. GPS höjdenfrån mätningarna har stor felmarginal jämfört med den verkliga höjden samt när den jämförsmed den beräknade höjden från barometern.Genom att utföra en numerisk integration på accelerometer-data kom vi fram till att det är möjligtatt beräkna ungefär hur långt man har färdats med en hiss, dock att vissa detaljer måste tasi beaktning.<br>This report summarizes the results of a degree Bachelor of engineering in Computer Scienceconducted by two students at Malmo University.Work aim was to conduct a variety of experiments with accelerometer, barometer and GPS in amodern smartphone. A number of scenarios for a possible sensor use in applications formulatedto guided experiments. Data is carefully documented and analyzed, with the intention tocreate a database of information for future studies. Analysis of the data includes the altitudedetermination in nature and in buildings using barometric sensor, geographic location usingGPS, speed and acceleration during an elevator journey with the help of accelerometer.The report contains a comprehensive literature review on the use of sensors for indoorpositioning.From our analysis of the measurement data, we conclude that it is possible to calculate thealtitude from barometric- information but good accuracy if there are optimum circumstances.GPS altitude from our measurements show faulty height by a large margin compared with theactual height and when it is compared with the calculated height of the barometer the barometricheight is closer to the actual height.By performing a numerical integration of the accelerometer data, the results show that it ispossible to calculate approximately how far you have traveled in meters in an elevator, howeverthere are some things that must be taken into consideration.
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Ciotirca, Lavinia-Elena. "System design of a low-power three-axis underdamped MEMS accelerometer with simultaneous electrostatic damping control." Phd thesis, Toulouse, INPT, 2017. http://oatao.univ-toulouse.fr/17939/7/CIOTIRCA_L.pdf.
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Recently, consumer electronics industry has known a spectacular growth that would have not been possible without pushing the integration barrier further and further. Micro Electro Mechanical Systems (MEMS) inertial sensors (e.g. accelerometers, gyroscopes) provide high performance, low power, low die cost solutions and are, nowadays, embedded in most consumer applications. In addition, the sensors fusion has become a new trend and combo sensors are gaining growing popularity since the co-integration of a three-axis MEMS accelerometer and a three-axis MEMS gyroscope provides complete navigation information. The resulting device is an Inertial measurement unit (IMU) able to sense multiple Degrees of Freedom (DoF). Nevertheless, the performances of the accelerometers and the gyroscopes are conditioned by the MEMS cavity pressure: the accelerometer is usually a damped system functioning under an atmospheric pressure while the gyroscope is a highly resonant system. Thus, to conceive a combo sensor, aunique low cavity pressure is required. The integration of both transducers within the same low pressure cavity necessitates a method to control and reduce the ringing phenomena by increasing the damping factor of the MEMS accelerometer. Consequently, the aim of the thesis is the design of an analog front-end interface able to sense and control an underdamped three-axis MEMSaccelerometer. This work proposes a novel closed-loop accelerometer interface achieving low power consumption The design challenge consists in finding a trade-off between the sampling frequency, the settling time and the circuit complexity since the sensor excitation plates are multiplexed between the measurement and the damping phases. In this context, a patenteddamping sequence (simultaneous damping) has been conceived to improve the damping efficiency over the state of the art approach performances (successive damping). To investigate the feasibility of the novel electrostatic damping control architecture, several mathematical models have been developed and the settling time method is used to assess the damping efficiency. Moreover, a new method that uses the multirate signal processing theory and allows the system stability study has been developed. This very method is used to conclude on the loop stability for a certain sampling frequency and loop gain value. Next, a 0.18μm CMOS implementation of the entire accelerometer signal chain is designed and validated.
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Sosopoulos, Konstantinos, and Michael Tareke Woldu. "IoT smart athletics : Boxing glove sensors implementing machine learning for an integrated training solution." Thesis, Högskolan Kristianstad, Fakulteten för naturvetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hkr:diva-21955.
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It is very common in everyday life for people to use data generated by sensors like accelerometers and gyroscopes, whether they are on the mobile phone, smartwatch or other smart devices, for analysis of their movement or tracking their habits. This study is focused on boxing, and proposes a test where the generated data are put through machine learning algorithms in order to output information on the type of punch thrown by the user. Furthermore, the possibility of implementing ML on Android is examined. This thesis was performed by conducting a literature study, and an experimental study. For the literature study, researches similar to this were examined to gather information and insight on what the most common practices are, regarding the setup of the device used to collect the data, both in terms of sensor placement on the body and sensor setup like the optimal data output rates. The experimental part was conducted using custom hardware implementing an accelerometer and a gyroscope in which the wearer of this device would proceed to throw 6 types of punches (jab, cross, left & right uppercut, and left & right hook) to generate the data to be analyzed. It was technically possible to use Android for ML, but it was the least optimum way to execute the algorithms, so a PC was used instead. After putting the data through multiple ML algorithms, the results show that with our current hardware set up it was not possible for the ML algorithms to adequately classify the type of punches with mediocre accuracy scores ranging from 37.37% - 59.16% depending on the algorithm.
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Бердичевський, Дмитро Володимирович. "Засіб для позиціонування рухомих об'єктів в просторі". Bachelor's thesis, КПІ ім. Ігоря Сікорського, 2021. https://ela.kpi.ua/handle/123456789/42202.
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В даній дипломній роботі було промоделювано засіб для знаходження координат об’єкта в просторі щоб полегшити та зменшити час знаходження дефекту на ділянці.
У першому розділі дипломної роботи представлено теоретичні відомості про технології локального позиціонування. А також, наведено переваги та недоліки даних технологій, а також обґрунтовано вибір певної технології до даної дипломної роботи. У другому розділі приведено методи локального позиціонування та висновок щодо застосування даних методів. В третьому розділі описано MEMS датчики та короткі відомості про них, математичну частину даних датчиків, знаходження кутів Ейлера, характеристики, а також вибір датчиків до даної дипломної роботи. В четвертому розділі приведено функціональну та принципову електричну схему, опис цієї схеми, а також алгоритм знаходження координат нашого дефекту.<br>In this thesis, a tool for finding the coordinates of the object in space was modeled to facilitate and reduce the time of finding the defect on the site.
The first section of the thesis presents theoretical information about local positioning technologies. Also, the advantages and disadvantages of these technologies are given, as well as the choice of a certain technology for this thesis is substantiated. The second section presents the methods of local positioning and the conclusion on the application of these methods. The third section describes MEMS sensors and brief information about them, the mathematical part of the sensor data, finding the Euler angles, characteristics, as well as the choice of sensors for this thesis. In the fourth section the functional and basic electric scheme, the description of this scheme, and also algorithm of finding of coordinates of our defect is resulted.
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Eccher, Luca. "Identificazione di attività motorie a partire da misure con sensori indossabili: una revisione critica della letteratura." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amslaurea.unibo.it/6926/.
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La revisione qui riportata valuta tutte le modalità di identificazione di task motori e posturali attraverso l'uso di sensori indossabili, principalmente accelerometri. Essa ha lo scopo di illustrare i sensori e gli algoritmi utilizzati in 23 articoli scelti in base alla loro qualità secondo una metodologia personalizzata di ricerca per fare il punto degli studi in questo campo, fino a questo momento. I dati estratti vengono utilizzati per individuare gli aspetti chiave riportati negli articoli, specialmente riguardanti l'algoritmo, focus della nostra revisione. Secondo questo criterio vengono selezionati 13 articoli, i quali si soffermano maggiormente sui modelli di approccio utilizzati, al fine di ottenere la più elevata accuratezza nell'identificazione. Questa in generale varia tra l'80-90% per i task motori più conosciuti(camminata, corsa e altri) mentre rimane limitata, intorno al 60-70% quando vengono analizzati i movimenti specifici degli arti superiori o inferiori.
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Lavieri, Rodrigo Sauri. "Métodos de navegação inercial aplicados a lançamentos submarinos." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/3/3135/tde-06042011-131110/.
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A demanda crescente por petróleo impulsiona a exploração marítima desta riqueza para águas cada vez mais profundas. O aumento da lâmina dágua exige novas soluções de engenharia principalmente no que se refere à operação de unidades flutuantes de produção. Dentre os desafios impostos pelos novos ambientes de prospecção, destaca-se o processo de ancoragem, neste texto explorado sob a ótica da chamada estaca-torpedo. Embora já tenha sido empregada com sucesso na ancoragem de risers e FPSOs, esta solução encontra-se em constante desenvolvimento, sendo a principal fonte de informação acerca dos lançamentos da estaca-torpedo proveniente de uma unidade de medição inercial (UMI). A presente pesquisa baseou-se no estudo desta UMI e teve como objetivos principais verificar seu desempenho e compreender a empregabilidade deste tipo de monitoração em operações submarinas de maneira mais ampla. Além do estudo detalhado dos sensores, foi dada especial atenção aos algoritmos empregados no tratamento dos sinais provenientes da UMI. Foram estudadas técnicas de correção do sinal, quantificação de ruído, desafios inerentes aos sistemas do tipo strapdown e o processo de integração. Como resultado final foi desenvolvido um algoritmo baseado em quatérnios, alternativo ao atualmente empregado para o processamento dos sinais provenientes da UMI que equipa a estaca-torpedo.<br>The increasing demand on crude oils constantly pushes the offshore exploitation to deeper waters. As the water depth grows, new engineering challenges arise, especially concerning to the operation of floating production units. Among all the technical issues inherent to the new prospection environment, the mooring system is a significant topic and the development of the torpedo-pile takes place at this scenario. This mooring system has already been successfully applied in anchoring risers and FPSOs; nevertheless, it is in constant study and improvement. The major source of information about the torpedo-pile deployment comes from an inertial measurement unit (IMU). The research presented here is based on this IMU and had as main objective verify its performance and also comprehend the applicability of such kind of unit in other subsea processes. Along with the detailed sensors study, it was given special attention to the algorithms used to process the signals from the IMU. Signal correction techniques and noise quantification were investigated as long as challenges intrinsically related to strapdown navigation systems and the integration process. In the end, an alternative data processing algorithm based on quaternions was produced, to be employed in torpedo-pile launching together with its IMU.
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Marquet, Noémie. "Towards a hybrid electrostatic/atomic accelerometer for future space missions : study of rotation impact on a cold atom interferometer and mitigation strategy." Electronic Thesis or Diss., université Paris-Saclay, 2024. http://www.theses.fr/2024UPASP169.
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Le but des missions spatiales de gravimétrie est de mesurer le champ de gravité avec une grande précision. Les données récoltées sont utilisées en sciences du climat, en hydrologie, en géophysique et pour mieux comprendre le réchauffement climatique. Ces missions embarquent actuellement des accéléromètres électrostatiques avec une grande sensibilité mais dérivant à long terme. Cette dérive peut être corrigée en recalibrant l'accéléromètre électrostatique avec un accéléromètre à atomes froids ayant une plus importante stabilité. De tels accéléromètres utilisent l'interférométrie atomique pour mesurer l'accélération et une des difficultés de la mesure spatiale est la chute de contraste de l'interféromètre à cause de la rotation du satellite autour de la Terre. Dans cette étude, nous avons mis en place expérimentalement une méthode pour limiter l'impact de la rotation sur l'interféromètre. Le dispositif expérimental est la combinaison d'un accéléromètre électrostatique et d'un interféromètre à atomes froids. La masse d'épreuve de l'électrostatique est employée comme miroir de rétro-réflexion pour l'interféromètre et est très bien contrôlée selon les six dégrées de liberté de l'espace. La méthode utilisée pour limiter l'impact de la rotation consiste à tourner le miroir pour garder la direction de mesure constante pendant l'interféromètre. Avec cette méthode de compensation de la rotation, 99% du contraste a été récupéré. De plus, la phase de l'interféromètre causée par la rotation a été mesuré et modélisée. Avec un modèle fiable, cette phase supplémentaire peut être corrigée de la mesure. Finalement, les performances attendues d'un accéléromètre atomique compensé de la rotation à bord d'un satellite ont été étudiées. Avec les hypothèses choisies, la rotation serait à l'origine d'une incertitude de 7 x 10⁻¹⁰ ms⁻ ² sur la mesure de l'accélération pour un temps d'interrogation de 1 s<br>Space gravimetry missions aim to determine the Earth gravity field with great accuracy. The data gathered are very useful in the sciences of climatology, hydrology or geophysics and to understand global climate change. These missions board state-of-the-art space electrostatic accelerometers displaying a very good sensitivity but also a long-term drift. By combining an electrostatic accelerometer with a very stable cold atom accelerometer, the correction of this drift is possible. Such accelerometers principle relies on atomic interferometry and one of the difficulties of space measurements is the interferometer contrast loss due the satellite rotation around the Earth. In this work, we experimentally implemented a method to limit the impact of rotation of the interferometer with an original setup. The hybrid lab prototype is the combination of an electrostatic accelerometer and a cold atom interferometer. The proof-mass of the electrostatic accelerometer, very well controlled in angle and position, is employed as an actuated retro-reflection mirror for the interferometer. The method tested to limit the rotation impact, consists in the rotation of the retro-reflection mirror to keep the direction of measurement constant during the interferometer. With the rotation compensation method, a contrast recovery up to 99% was demonstrated. Moreover, the impact of such a method on the phase shift bias was also measured and confronted to models. With an accurate model, the phase shift bias can be corrected from the measurement. Lastly, a study of the expected performances of a rotation compensated atom accelerometer boarded on a satellite was conducted. Under the considered hypothesis, the rotation should lead to an acceleration uncertainty of 7 x 10⁻¹⁰ ms⁻ ² for a 1 s interrogation time
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Bränn, Jesper. "Smartphone sensors are sufficient to measure smoothness of car driving." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-208895.
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This study aims to look at whether or not it is sufficient to only use smartphone sensors to judge if someone who is driving a car is driving aggressively or smoothly. To determine this, data were first collected from the accelerometer, gyroscope, magnetometer and GPS sensors in the smartphone as well as values based on these sensors from the iOS operating system. After this the data, together with synthesized data based on the collected data, were used to train an artificial neural network.The results indicate that it is possible to give a binary judgment on aggressive or smooth driving with a 97% accuracy, with little model overfitting. The conclusion of this study is that it is sufficient to only use smartphone sensors to make a judgment on the drive.<br>Den här studien ämnar till att bedöma huruvida smartphonesensorer är tillräckliga för att avgöra om någon kör en bil aggressivt eller mjukt. För att kunna avgöra detta så samlades först data in från accelerometer, gyroskop, magnetometer och GPS-sensorerna i en smartphone, tillsammans med värden baserade på dessa data från iOS-operativ-systemet. Efter den datan var insamlad tränades ett artificiellt neuronnät med datan.Resultaten indikerar att det är möjligt att ge ett binärt utlåtande om aggressiv kontra mjuk körning med 97% säkerhet, och med liten överanpassning. Detta innebär att det är tillräckligt att enbart använda smartphonesensorer för att avgörande om körningen var mjuk eller aggressiv.
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Sadat, Md Anwar. "LOW POWER CMOS CIRCUIT DESIGN AND RELIABILITY ANALYSIS FOR WIRELESS ME." Doctoral diss., University of Central Florida, 2004. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3390.
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A sensor node 'AccuMicroMotion' is proposed that has the ability to detect motion in 6 degrees of freedom for the application of physiological activity monitoring. It is expected to be light weight, low power, small and cheap. The sensor node may collect and transmit 3 axes of acceleration and 3 axes of angular rotation signals from MEMS transducers wirelessly to a nearby base station while attached to or implanted in human body. This dissertation proposes a wireless electronic system-on-a-single-chip to implement the sensor in a traditional CMOS process. The system is low power and may operate 50 hours from a single coin cell battery. A CMOS readout circuit, an analog to digital converter and a wireless transmitter is designed to implement the proposed system. In the architecture of the 'AccuMicroMotion' system, the readout circuit uses chopper stabilization technique and can resolve DC to 1 KHz and 200 nV signals from MEMS transducers. The base band signal is digitized using a 10-bit successive approximation register analog to digital converter. Digitized outputs from up to nine transducers can be combined in a parallel to serial converter for transmission by a 900 MHz RF transmitter that operates in amplitude shift keying modulation technique. The transmitter delivers a 2.2 mW power to a 50 Ù antenna. The system consumes an average current of 4.8 mA from a 3V supply when 6 sensors are in operation and provides an overall 60 dB dynamic range. Furthermore, in this dissertation, a methodology is developed that applies accelerated electrical stress on MOS devices to extract BSIM3 models and RF parameters through measurements to perform comprehensive study, analysis and modeling of several analog and RF circuits under hot carrier and breakdown degradation.<br>Ph.D.<br>Department of Electrical and Computer Engineering<br>Engineering and Computer Science<br>Electrical Engineering
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Santos, Felipe Silva. "Abstração de eventos de sensores para dispositivos de interação." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/55/55134/tde-03072008-100619/.
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Vários tipos de sensores têm sido explorados na construção de mecanismos para capturar, por exemplo, movimentos dos olhos, da cabeça, ou do tórax do usuário. A construção de dispositivos de interação baseados em tais sensores demandam conhecimentos especializados. O trabalho aqui reportado teve como objetivo desenvolver uma arquitetura de componentes de hardware e software que fornece, como dados de entrada para aplicações computacionais, eventos capturados de sensores tais como os que detectam inclinação, rotação e aceleração. A pesquisa envolveu a concepção e a implementação de uma arquitetura em camadas que possui, em sua base, uma camada de hardware composta por um conjunto de sensores e circuitos apropriados que mensuram eventos físicos e, nas demais camadas, componentes de software que permitem associar uma semântica de dados de entrada para aplicações aos dados primitivos provenientes dos sensores e das camadas intermediárias. Como resultado, a arquitetura disponibiliza os dados dos sensores como eventos em alto nível, que podem ser associados a operações de interação usuário-computador típicas de um mouse, de um teclado ou de um joystick, por exemplo. A implementação de um dispositivo de interação baseado em sensores é facilitada, por um lado, pelo fato de o tratamento de erros associado ao uso de sensores poder ter sido realizado nas camadas inferiores e, por outro, pelo fato de os dados serem apresentados em um alto nível de abstração que não exige conhecimento específico sobre o uso do hardware associado. Como estudo de caso, criouse um dispositivo de interação que permite interações típicas de um mouse, e que pode ser usado por usuários tetraplégicos, que possuam controle fino dos movimentos da cabeça e ausência de deficiências visuais<br>Some types of sensors have been explored in the construction of mechanisms to capture, for example, movements of the eyes, the head, or the thorax of the user. The construction of devices of interaction based in such sensors demand specialized knowledge. The work reported here had as objective to develop an architecture of components of the hardware and software that it supplies, as given of entrance for computational applications, captured events of sensors such as the ones that detect inclination, rotation and acceleration. The research involved the conception and the implementation of a in layers architecture that it possesss, in its base, a composed layer of the hardware for a set of sensors and appropriate circuits that measure physical events and, in the too much layers, software components that allow to associate a semantics of data of entrance for applications to the primitive data proceeding from the sensors and the intermediate layers. As result, the architecture makes available the data of the sensors as events in high level, that can be associates the operations of typical interaction one user-computer mouse, of a keyboard or one joystick, for example. The implementation of a device of interaction based on sensors is facilitated, on the other hand, for the fact of the treatment of errors associated to the use of sensors to be able to have been carried through in inferior layers e, for another one, the fact of the data to be presented in one high level of abstraction that does not demand specific knowledge on the use of the associated hardware. As case study, an interaction device was created that allows typical interactions of one mouse, and that it can be used for tetraplegic users, who possess fine control of the movements of the head and absence of visual deficiencies
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Dvořák, Jan. "Inerciální navigační jednotka." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-263604.
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This thesis is focused on the design and realisation of inertial navigation unit INS. The unit is capable to measure, store and send data to a PC in real-time for a later offline processing. The first part of the thesis introduces the reader with the basic principles of accelerometers, gyroscopes and MEMS sensors. An introduction to coordinate systems and measuring errors is also included. The second and third part of the thesis deals with the analysis of the solution and the implementation of the INS unit. The fourth part of the document is dedicated to the software for the INS unit. This thesis concludes with explanation how the gathered data are processed.
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Olnén, Johanna, and Julia Sommarlund. "Activity Recognition Using IoT and Machine Learning." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-295603.
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Internet of Things devices, such as smartphonesand smartwatches, are currently becoming widely accessible andprogressively advanced. As the use of these devices steadilyincreases, so does the access to large amounts of sensory data.In this project, we developed a system that recognizes certainactivities by applying a linear classifier machine learning modelto a data set consisting of examples extracted from accelerometersensor data. We obtained the data set by collecting data from amobile device while performing commonplace everyday activities.These activities include walking, standing, driving, and ridingthe subway. The raw accelerometer data was then aggregatedinto data points, consisting of several informative features. Thecomplete data set was subsequently split into 80% training dataand 20% test data. A machine learning algorithm, in this case,a support vector machine, was presented with the training dataset and finally classified all test data with a precision higher than90%. Hence, meeting our set objective to build a service with acorrect classification score of over 90%.Human activity recognition has a large area of application,including improved health-related recommendations and a moreefficiently engineered system for public transportation.<br>Internet of Things-enheter, så som smarta telefoner och klockor, blir numera allt mer tillgängliga och tekniskt avancerade. Eftersom användningen av dessa smarta enheter stadigt ökar, ökar också tillgången till stora mängder data från sensorer i dessa enheter. I detta projekt utvecklade vi ett system som känner igen vissa aktiviteter genom att tillämpa en linjär klassificerande maskininlärningsmodell på en uppsättning data som extraherats från en accelerometer, en sensor i en smart telefon. Datauppsättningen skapades genom att samla in data från en smart telefon medan vi utförde vardagliga aktiviteter, så som promenader, stå stilla, köra bil och åka tunnelbana. Rå accelerometerdata samlades in och gjordes om till datavektorer innehållandes statistiska mått. Den totala datauppsättningen delades sedan upp i 80% träningsdata och 20% testdata. En maskininlärningsalgoritm, i detta fall en supportvektormaskin, introducerades med träningsdatan och klassificerade slutligen testdatan med en precision på över 90%. Därmed uppfylldes vårt uppsatta mål med att bygga en tjänst med en korrekt klassificering på över 90%. Igenkänning av mänsklig aktivitet har ett stort användningsområde, och kan bidra till förbättrade hälsorekommendationer och en mer effektiv kollektivtrafik.<br>Kandidatexjobb i elektroteknik 2020, KTH, Stockholm
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Nohejl, Petr. "Rozšířená realita pro platformu Android." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2011. http://www.nusl.cz/ntk/nusl-237078.
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This thesis describes design and implementation of augmented reality system for Android platform using location sensors. The application serves as a navigation and displays geographical points of interest. Thesis deals with augmented reality on mobile devices, describes design of own framework and mentions the details about implementation of selected problems. Finally, the results are evaluated.
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Mitschke, Christian, Pierre Kiesewetter, and Thomas L. Milani. "The Effect of the Accelerometer Operating Range on Biomechanical Parameters: Stride Length, Velocity, and Peak Tibial Acceleration during Running." Universitätsbibliothek Chemnitz, 2018. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-232621.
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Previous studies have used accelerometers with various operating ranges (ORs) when measuring biomechanical parameters. However, it is still unclear whether ORs influence the accuracy of running parameters, and whether the different stiffnesses of footwear midsoles influence this accuracy. The purpose of the present study was to systematically investigate the influence of OR on the accuracy of stride length, running velocity, and on peak tibial acceleration. Twenty-one recreational heel strike runners ran on a 15-m indoor track at self-selected running speeds in three footwear conditions (low to high midsole stiffness). Runners were equipped with an inertial measurement unit (IMU) affixed to the heel cup of the right shoe and with a uniaxial accelerometer at the right tibia. Accelerometers (at the tibia and included in the IMU) with a high OR of ±70 g were used as the reference and the data were cut at ±32, ±16, and at ±8 g in post-processing, before calculating parameters. The results show that the OR influenced the outcomes of all investigated parameters, which were not influenced by tested footwear conditions. The lower ORs were associated with an underestimation error for all biomechanical parameters, which increased noticeably with a decreasing OR. It can be concluded that accelerometers with a minimum OR of ±32 g should be used to avoid inaccurate measurements.
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Nicolau, Murilo. "Esfera instrumentada de baixo custo para monitoramento de impactos e temperatura durante processos pos-colheita." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/259036.
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Orientador: Fabiano Fruett<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação<br>Made available in DSpace on 2018-08-14T00:04:04Z (GMT). No. of bitstreams: 1
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Previous issue date: 2009<br>Resumo: O Brasil é um dos maiores produtores mundiais de frutas e hortaliças. No entanto as perdas de produtos hortículas, devido a danos físicos e estresse térmico, são estimadas em cerca de 30%a 40%, podendo chegar a 50 % para certos produtos. As perdas pós-colheita de hortícolas tem início na sua colheita e pode culminar em seu descarte antes mesmo deste chegar ao consumidor final. O conhecimento das variáveis geradoras deste desperdício, suas influências e inter-relações pode colaborar para minimizar o problema. Apresentamos neste trabalho um instrumento capaz de monitorar os impactos e a temperatura durante a colheita e pós-colheita. Este instrumento, denominado Fruta Eletrônica, foi projetado para ser uma ferramenta acessível ao produtor rural. A esfera instrumentada mede e armazena impactos tri-axiais na faixa de 0,5g até 250g e temperatura na faixa de 0° C até 80º C. Testes em campo realizados em uma linha de beneficiamento de laranjas na cidade de Eng. Coelho, SP, mostram que esse instrumento pode fornecer informações úteis que colaboram na identificação dos pontos de estresse mecânico e térmico, os quais os frutos são submetidos.<br>Abstract: Brazil is one of the largest worldwide producers of fruit and vegetables. However, the loss of horticultural products due to physical damage and thermal stress is estimated at about 30 % to 40 %, even 50 % for certain products. The process that degrades the quality of vegetables starts during its harvest and can culminate in its disposal even before reaching the final consumer. The knowledge of the variables that act in this waste generating process, their influences and inter-relationships can help to minimize the problem. In this work, we present a tool capable of monitoring the impacts and temperature during the postharvest. This instrument, called Fruta Eletrônica, was designed to be an accessible tool for the farmers. This instrument measures and stores triaxial impacts from 0.5 g to 250 g and temperatures between 0 °C and 80 °C. Field tests, carried out in an orange packing line treatment in Eng. Coelho city, show that this instrument can provide useful information to assist identifying the points of mechanical and thermal stress in which fruits are submitted.<br>Mestrado<br>Eletrônica, Microeletrônica e Optoeletrônica<br>Mestre em Engenharia Elétrica
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Ahmadi, Matthew. "Application of machine learning approaches for activity recognition and energy expenditure prediction in free living children and adolescents." Thesis, Queensland University of Technology, 2020. https://eprints.qut.edu.au/206178/1/Matthew%20Nguyen_Ahmadi_Thesis.pdf.
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This thesis was the first to comprehensively evaluate the application of machine learning approaches for physical activity assessment under real world conditions among children with unique movement patterns. This included preschool age children and children with cerebral palsy. Collectively, the findings from this thesis conclude activity classification models trained on laboratory-based data fail to generalise to a real-world environment and models trained on free-living data have superior accuracy. In contrast, energy expenditure prediction models trained on laboratory-based data generalise to real world environments with no further improvements attained when trained on free-living data.
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Ocak, Ilker Ender. "A Tactical Grade Mems Acceleroemeter." Phd thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612724/index.pdf.
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Micromachining technologies enabled the use of miniaturized transducers in many high technology sensing systems. These transducers have many advantages like small-size, low-cost and high-reliability. One of the applications micro-machined transducers are used is inertial navigation systems, where the exact position of a moving frame is continuously monitored by tracking the linear and angular motions of the frame. Other than navigation applications, inertial sensors are used in health and military applications as well as consumer electronics. Today accelerometers capable of measuring accelerations from 0.5g-1g range up to several thousand g&rsquo<br>s are commercially available in the market which have been fabricated using micromachining technologies. The aim of this research is to develop such a state-of-the-art micro-machined accelerometer system, whose performance is expected to reach tactical-grade level.
In order to achieve these performance values a MATLAB algorithm is developed to optimize the accelerometer performances in the desired levels. Expected performance parameters of the designed accelerometer structures are extracted from the simulations done by both Coventorware finite element modeling tool and MATLAB. Designed structures are then fabricated with silicon-on-glass, dissolved wafer and dissolved epitaxial wafer processes. These fabrication results are compared and it is observed that highest yield accelerometers are fabricated with the SOG process. But these accelerometers could not be able to satisfy tactical grade performance parameters. Best performances are obtained with DWP, but due to high internal stress, yield of the sensors were very low. DEWP increased the yield of this process from 2-3% to 45-50% but the expected operation range of the designs dropped to ±<br>12.5g range. Using the fabricated accelerometers in DEWP a three axial accelerometer package is prepared and tests results proved that this three axial accelerometer system was satisfying the tactical grade requirements. In addition to these a three axial monolithic accelerometer fabrication technique is proposed and sensors are designed which are suitable for this process.
Best performances achieved with single axis accelerometers were 153µ<br>g/&radic<br>Hz noise floor, 50µ<br>g bias drift, 0.38% non-linearity and a maximum operation range of 33.5g which has the higher dynamic range among its counterparts in the literature. Performance results achieved with the three axes accelerometer were ~150µ<br>g bias drift, <<br>200µ<br>g/&radic<br>Hz noise density, ~0.4% non-linearity with higher than ±<br>10g operation range.
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Murín, Michal. "Augmented Reality for Mobile Devices for Precise Urban Navigation." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2013. http://www.nusl.cz/ntk/nusl-236197.
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Diplomová práce je zaměřená na rozšířenou realitu a její realizaci pro mobilní platformu Android. V teoretické části je kladen důraz na obeznámení se s principy rozšířené reality, možnostmi její realizace pro mobilní platformu Android, která je také podrobněji představena. V praktické části se dále zaměřuje na návrh a realizaci knihovny a aplikace využívající tuhle knihovnu pro tvorbu rozšířené reality na platformě Android pomocí GPS a polohových senzorů. Aplikace slouží jako navigace a zobrazuje cestu ke konkrétnímu cíly, jak v podobě rozšířené reality, tak i na klasické dvourozměrné mapě. Práce podrobně popisuje navrhované řešení knihovny a aplikace a jejich implementaci. Nakonec popisuje testování, zhodnocuje dosažené výsledky a diskutuje nedostatky výsledného řešení a možnosti jeho vylepšení, respektive rozšíření.
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Bezdíček, Jan. "Telemetrie pro formuli Dragon IV." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2014. http://www.nusl.cz/ntk/nusl-236045.
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The aim of this master's thesis was to design and construct complete telemetry system for the student formula Dragon IV constructed for international Formula Student competition. At first, the work deals with the measurement of the physical quantities, telemetry system and automotive sensors of the formula, their mutual communication and communication with the CAN bus. It also describes the procedure of hardware design including choosing right inertial sensors and a GPS module and their using in telemetry system. The work contains materials for production of two-layer printed circuit board extending the microcomputer BeagleBone Black on the inertial sensors and the GPS module. The bigger part of the telemetry system is the firmware for hardware and software for the computer user. Both written in programming language C++ and C# are included in this work as well. This user application serves for wireless receiving data from the hardware and their showing and logging. In addition this user application can be used for wireless hardware configuration. The final product is the complete telemetry system and it is suitable for selling to end customer.
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Axelsson, Henrik, and Daniel Wass. "Machine Learning for Activity Recognition of Dumpers." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-260256.
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The construction industry has lagged behind other industries in productivity growth rate. Earth-moving sites, and other practices where dumpers are used, are no exceptions. Such projects lack convenient and accurate solutions for utilization mapping and tracking of mass flows, which both currently and mainly rely on manual activity tracking. This study intends to provide insights of how autonomous systems for activity tracking of dumpers can contribute to the productivity at earthmoving sites. Autonomous systems available on the market are not implementable to dumper fleets of various manufacturers and model year, whereas this study examines the possibilities of using activity recognition by machine learning for a system based on smartphones mounted in the driver’s cabin. Three machine learning algorithms (naive Bayes, random forest and feed-forward backpropagation neural network) are trained and tested on data collected by smartphone sensors. Conclusions are that machine learning models, and particularly the neural network and random forest algorithms, trained on data from a standard smartphone, are able to estimate a dumper’s activities at a high degree of certainty. Finally, a market analysis is presented, identifying the innovation opportunity for a potential end-product as high.<br>Byggnadsbranschen har halkat efter andra branscher i produktivitetsökning. Markarbetesprojekt och andra arbeten där dumprar används är inga undantag. Sådana projekt saknar användarvänliga system för att kartlägga maskinutnyttjande och massaflöde. Nuvarande lösningar bygger framförallt på manuellt arbete. Denna studie syftar skapa kännedom kring hur autonoma system för aktivitetsspårning av dumprar kan öka produktiviteten på markarbetesprojekt. Befintliga autonoma lösningar är inte implementerbara på maskinparker med olika fabrikat eller äldre årsmodeller. Denna studie undersöker möjligheten att applicera aktivitetsigenkänning genom maskininlärning baserad på smartphones placerade i förarhytten för en sådan autonom lösning. Tre maskininlärningsalgoritmer (naive Bayes, random forest och backpropagation neuralt nätverk) tränas och testas på data från sensorer tillgängliga i vanliga smartphones. Studiens slutsatser är att maskininlärningsmodeller, i synnerhet neuralt nätverk och random forest-algoritmerna, tränade på data från vanliga smartphones, till hög grad kan känna igen en dumpers aktiviteter. Avslutningsvis presenteras en marknadsanalys som bedömer innovationsmöjligheten för en eventuell slutprodukt som hög.
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Kepenek, Reha. "Capacitive Cmos Readout Circuits For High Performance Mems Accelerometers." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12609310/index.pdf.
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This thesis presents the development of high resolution, wide dynamic range sigma-delta type readout circuits for capacitive MEMS accelerometers. Designed readout circuit employs fully differential closed loop structure with digital output, achieving high oversampling ratio and high resolution. The simulations of the readout circuit together with the accelerometer sensor are performed using the models constructed in Cadence and Matlab Simulink environments. The simulations verified the stability and proper operation of the accelerometer system. The sigma-delta readout circuit is implemented using XFab 0.6 µ<br>m CMOS process. Readout circuit is combined with Silicon-On-Glass (SOG) and Dissolved Wafer Process (DWP) accelerometers. Both open loop and closed loop tests of the accelerometer system are performed. Open loop test results showed high sensitivity up to 8.1 V/g and low noise level of 4.8 µ<br>g/&<br>#61654<br>Hz. Closed loop circuit is implemented on a PCB together with the external filtering and decimation electronics, providing 16-bit digital output at 800 Hz sampling rate. High acceleration tests showed ±<br>18.5 g of linear acceleration range with high linearity, using DWP accelerometers. The noise tests in closed loop mode are performed using Allan variance technique, by acquiring the digital data. Allan variance tests provided 86 µ<br>g/&<br>#61654<br>Hz of noise level and 74 µ<br>g of bias drift. Temperature sensitivity tests of the readout circuit in closed loop mode is also performed, which resulted in 44 mg/º<br>C of temperature dependency.
Two different types of new adaptive sigma-delta readout circuits are designed in order to improve the resolution of the systems by higher frequency operation. The two circuits both change the acceleration range of operation of the system, according to the level of acceleration. One of the adaptive circuits uses variation of feedback time, while the other circuit uses multi-bit feedback method. The simulation results showed micro-g level noise in closed loop mode without the addition of the mechanical noise of the sensor.
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Kovaleski, Joao Luiz. "Etude, modélisation et réalisation de capteurs d'accélération et force à base de polymère piézoélectrique PVF2." Grenoble 1, 1992. http://www.theses.fr/1992GRE10122.
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Le pvf2 s'avere bien adapte chaque fois que l'une ou moins de ses proprietes intrinseques est exploitee. En vue de la realisation de capteurs accelerometriques, nous avons etudie les proprietes du pvf2 et nous avons analyse le comportement d'une lame de pvf2 soumise a une contrainte de compression. Nous avons developpe des modeles electriques du pvf2 qui nous permettent d'effectuer des simulations a l'aide du logiciel spice. Ces modeles nous ont permis de definir les caracteristiques theoriques de nos capteurs que nous avons pu correler avec les resultats experimentaux. A la suite de ces etudes theoriques nous avons realise des capteurs accelerometriques. Parmi ceux-ci nous retiendrons l'accelerometre sismique et le capteur d'activite. Ces deux capteurs sont interessants car ils presentent des caracteristiques extremes, tant sur le plan metrologique que sur le plan dimensionnel. Enfin, nous avons aussi a partir des etudes faites sur les caracteristiques des accelerometres a masses inertielles developpe un capteur gyrometrique susceptible de delivrer des signaux proportionnels aux grandeurs liees a un mouvement de rotation. En nous basant sur les travaux de modelisation, nous avons explore le domaine des basses frequences. A partir d'un algorithme de lecture de charge pour aborder le domaine des mesures de forces statiques, nous avons developpe une implementation capable de restituer une image de la force statique appliquee
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Mills, Euclid Weatley. "Mobile robotic design : robotic colour and accelerometer sensor." Thesis, University of Bradford, 2010. http://hdl.handle.net/10454/4436.
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This thesis investigates the problem of sensors used with mobile robots. Firstly, a colour sensor is considered, for its ability to detect objects having the three primary colours Red, Green and Blue (RGB). Secondly, an accelerometer was investigated, from which velocity was derived from the raw data using numerical integration. The purpose of the design and development of the sensors was to use them for robotic navigation and collision avoidance. This report presents the results of experiments carried out on the colour sensor and the accelerometer. A discussion of the results and some conclusions are also presented. It proved feasible to achieve the goal of detecting colours successfully but only for a limited distance. The accelerometer proved reliable but is not yet being applied in real time. Both the colour sensor and the accelerometer proved to be inexpensive. Some recommendations are made to improve both the colour sensor and the accelerometer sensors.
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Graham, Brian Barkley 1977. "Using an accelerometer sensor to measure human hand motion." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/86477.
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Thesis (S.B. and M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2000.<br>Includes bibliographical references (p. 108-110).<br>by Brian Barkley Graham.<br>S.B.and M.Eng.
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ALI, HASHIM. "Subject-dependent physical activity recognition using single sensor accelerometer." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2015. http://hdl.handle.net/10281/75865.
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Rapid advancement in the field of Artificial Intelligence, to be more specific in Machine Learning and Nanotechnology, strengthens hopes to better understand human mind. Ubiquitous Computing helped in the creation of intelligent environments pervaded by these visible and invisible devices, which are affecting and improving all aspects of human life. So, as a consequence, smart environments work on the behalf of humans for ease of comfort. The ultimate goal is to monitor humans without any awareness by them of computer interaction. The understanding of how humans will interact and make use of such systems is however largely unresolved and often not addressed collectively from both scientific and medical aspects in current research. A key to understanding such systems and their use is the observation that humans implicitly interact with their environment. The task of making this context information available to components in computer systems has become a prerequisite to move forward in human- computer interaction. Context awareness or more specifically how to create applications that are context aware is a central issue to Ubiquitous Computing research. Such research raises questions on context acquisition, context representation, distribution and abstraction, as well as programming paradigms, development support, and implications on human-computer interaction in general.
The aim of this thesis is to develop part of a ubiquitous care system to monitor elderly basic daily life activities; stand, sit, walk, lay and transitional activities. This thesis investigates the use of a wearable sensor (tri-axial accelerometer) to develop and evaluate the activity classification scheme with reliable accuracy in the real-world situations. The recognition of these activities is challenging because activities with similar posture are hard to discriminate (e.g. stand and sit). Moreover, this high similarity among activities is not uniform throughout the whole dataset which raises the question of how much training data would be required. Furthermore, the activity classification schemes proposed in literature are typically subject-independent; however there is lack of evidence that such subject-independent schemes have been successfully validated with elderly in uncontrolled situations.
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Schrader, Kale W. "Accelerometer Based Impact Localization and Scaling for Inflatable Space Structures." Fogler Library, University of Maine, 2010. http://www.library.umaine.edu/theses/pdf/SchraderKW2010.pdf.
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Arditi, Valentina. "Programmazione e calibrazione di un nodo sensore accelerometro." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2017.
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L'accelerometro è un sensore che trova attualmente largo e vario utilizzo nel settore biomedico. Obiettivo del lavoro di tesi sperimentale descritto nell'elaborato è stata la programmazione, la calibrazione e l’analisi dei dati prodotti da un nodo sensore in grado di rilevare un vettore accelerazione nelle sue tre componenti spaziali x, y e z.
L'accelerometro LIS2DH è stato programmato in ambiente software Atollic TrueSTUDIO, attraverso linguaggio C. Grazie alla scrittura delle apposite funzioni l’utente finale può impostarne a propria discrezione il range di misura tra i possibili ±2g, ±4g, ±8g, ±16g, la frequenza di campionamento da 1 Hz fino a 5.3 kHz e la risoluzione in bit di ciascun campione. Inoltre è stato sviluppato il codice per l'attivazione della memoria FIFO, nelle sue quattro modalità operative, e per la gestione ad interrupt della lettura dei dati da essa collezionati.
Per garantire maggiore affidabilità della misura ci si è occupati anche della creazione di una procedura di calibrazione semplice in termini di acquisizioni necessarie, eseguita autonomamente dal nodo sensore ed ottenibile ogni qualvolta l'utente lo ritenga necessario.
In ultimo è stata affrontata una parte di elaborazione dati, mirata soprattutto all'analisi vibrazionale. Essendo stato scritto il codice per la trasformazione nel dominio delle frequenze e il calcolo dell'algoritmo di peak detection, è possibile avere direttamente in uscita vettori contenenti le frequenze alle quali il segnale ha mostrato picchi di ampiezza importante.
Il nodo così programmato risulta più indirizzabile verso la specifica esigenza di ogni futuro utente, più performante in termini di risparmio di tempo di esecuzione e di potenza ed in grado di dare in uscita vettori x,y,z calibrati. Il lavoro sviluppato in questa attività di tesi può essere considerato rientrare anche nel più ampio tema della sensoristica finalizzata al monitoraggio dell’integrità strutturale.
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Guney, Metin G. "High Dynamic Range CMOS-MEMS Capacitive Accelerometer Array with Drift Compensation." Research Showcase @ CMU, 2018. http://repository.cmu.edu/dissertations/1155.
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This thesis explains the design, fabrication and characterization steps of a high dynamic range CMOS-MEMS capacitive accelerometer array and on-chip environmental sensors for bias drift compensation. Inertial navigation under harsh environments requires a high dynamic range accelerometer that can survive and provide continuous readout accuracy through shock events, while having a large dynamic range to capture fine-scale motions. The dynamic range target is set as 156 dB in accordance with navigation standard macro-electromechanical accelerometers, which corresponds to around 1 mG acceleration resolution in 50 kG input range. The small accelerometer cell design ensures shock survivability (e.g. up to 50 kG) by keeping the stress at the anchors below the fracture strength of thin-film oxide. Arraying multiple accelerometer cells in parallel lowers the fundamental thermomechanical noise limit set by the small mass of the individual accelerometer cells. Resonance frequency staggering between accelerometer cells suppresses ring-down oscillations. Parasitic capacitance of the high-impedance transduction signal is important to mitigate; undercut of the underlying silicon substrate and an aluminum etch of the top metal layer, incorporated in the CMOS-MEMS process flow, reduces the parasitic capacitance and improves sensitivity. PTAT temperature sensors, piezoresistive stress sensors and resonator-oscillators integrated across the accelerometer chip provide high-resolution environmental measurements for the compensation of long-term bias and scale factor drift. Simultaneous measurements from the accelerometer and environmental sensors demonstrate the correlation between environmental variations and long-term drift. Finite-element analysis shows that the scale factor stability of the accelerometer can be improved up to 1 ppm given the sensor array’s measurement resolution. The CMOS-MEMS accelerometer system-on-chip is fabricated in a TowerJazz 0.18 μm CMOS process. The post-CMOS MEMS processing steps are tuned to reduce the top metal milling and sidewall polymer deposition. A reactive ion etch recipe is developed for the removal of the top metal in order to reduce the parasitic capacitance and eliminate the risk of metal creep at spring beam anchors, thereby improve the bias stability. The PTAT temperature sensors have 3.1 mV/K measured sensitivity and 7.1 mK resolution with high repeatability. The compensation of the accelerometer readout for temperature variations down to 7.1 mK translates to 2.6 ppm scale factor stability for the accelerometer. The characterization of the stress sensors through the application of normal stress on the device package leads to an uncertainty in the amount of stress transferred to the stress sensors on the chip surface. The maximum measured stress sensitivity is 36.5 pV/Pa, which leads to 24.7 kPa stress resolution and translates to 1.7 ppm scale factor stability for the accelerometer without taking the stress attenuation into account. The measured sensitivity sets a lower bound on the sensitivity of the stress sensors implying that the stress resolution and the corresponding accelerometer scale factor stability is higher in practice. The measured frequency stability of the resonator-oscillator is 0.4 ppm, thereby the resonance frequency based variations of the accelerometer readout can be compensated to reach up to 0.8 ppm scale factor stability. However, the initial drift in the resonance frequency of the oscillators due to dielectric charging requires a long wait-time before these sensors can be used for accelerometer drift compensation. The accelerometer array is demonstrated to have 23.7 mG/√Hz noise floor and 70 mG bias stability. The maximum input acceleration applied on the device is limited to 4 kG by the split Hopkinson bar test setup. Improvement of the setup to transfer acceleration amplitudes up to 50 kG should validate the designed input range of the accelerometer array and lead to 117 dB dynamic range for the current design. The measurement bandwidth is fundamentally set by the 126 kHz resonance frequency of the accelerometer cells and can be further limited by filtering the readout signal to attenuate the transient oscillations faster. The nonlinearity of the accelerometer response is better than 1.2% in ±10 kG input range; however, it gets up to 19.0% in ±50 kG maximum input range. The long term bias drift of the accelerometer is shown to be correlated with the temperature and stress variations. Compensation of the accelerometer readout based on the stress and temperature sensor measurements leads to an observable improvement in the long term drift. However, the bias stability of the accelerometer is limited by excessive flicker noise in the system, which is believed to result from noise folding from higher frequencies. Suppression of the flicker noise in the system should allow for a more detailed study of the effect of environmental variations on the accelerometer readout and evaluation of more elaborate fitting algorithms for model based prediction and compensation of the bias drift to reach the target bias stability and dynamic range.
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Good, Daniel (Daniel Albert) 1979. "Design of a low power capacitive sensor for a micromachined accelerometer." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/16840.
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Thesis (M.Eng. and S.B.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2002.<br>Includes bibliographical references (leaves 72-73).<br>This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.<br>Anew possible commercial application for a micromachined accelerometer is for use in handheld devices such as personal digital assistants and cellular phones, as an intuitive method of data entry which does not consume space on the ever-shrinking exterior. These devices are battery powered, which imposes stringent power consumption limitations on any hardware added. To make an accelerometer a viable addition to a handheld device, a low power version was designed, with the other device parameters, such as measurement range and noise performance, tailored to be suitable for use in a handheld. The final design measures ±3 g's of acceleration with approximately 140 [mu]g/ [square root of]Hz of noise, consuming only 200 [mu]W of power.<br>by Daniel Good.<br>M.Eng.and S.B.
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Newell, George K. "A comparison of motion sensors during running." Virtual Press, 2006. http://liblink.bsu.edu/uhtbin/catkey/1348868.
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The assessment of physical activity is of great interest to the public and to researchers. One of the most popular and objective methods of assessing physical activity is using motion sensors such as pedometers and accelerometers. The purpose of this study was to assess the accuracy and reliability of step counting and energy expenditure estimation of two popular electronic pedometers and one accelerometer during running. In all step-counting trials, actual step counts were determined using a hand tally counter. Twenty subjects (18-40 years) were asked to volunteer to participate in the study. During the initial assessment subjects ran at five, six, seven, and eight miles per hour on a motor driven treadmill for ten minutes at each speed. While running they wore two pedometers and an accelerometer while oxygen consumption was measured. In the second assessment, all subjects ran a timed, self-paced mile around a 200-meter track while wearing all three activity monitors. In the third assessment, thirteen subjects ran at five, six, seven and eight miles per hour on a motor driven treadmill for three minutes at each speed to assess the step counting reliability of the devices. The three devices were accurate to within 1% at all speeds on the treadmill and on the self-paced track run. In addition, all three devices were reliable (r = 0.80). Caloric expenditure estimation accuracy the NL-2000 was ± 21% when expressed in both net and gross kcals. The Digi-walker was f 22% when assumed to be net kcals and ± 45% when assumed to be gross kcals. The Actigraph was accurate to ± 49% in terms of net calories. The results of the current study have shown that these devices are accurate and reliable for step counting at speeds between five and eight mph. However, their ability to assess caloric expenditure is not accurate at the same speeds. In conclusion, the application of these devices to runners is limited to highly accurate and reliable step counters.<br>School of Physical Education, Sport, and Exercise Science
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Khan, Nisar, and Fazlullah Khan. "Context based reminder system Supporting persons using Smartphone accelerometer data." Thesis, Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-4766.
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Context: Sensor base data is being used for many purposes in designing various memory aid systems for cognitive impaired people. Different memory aids or reminder systems are based on various technologies such as NFC, accelerometer, GPS and gyroscope. Smart phones are equipped with such sensors and can be used for assistance of persons. In this study we use smart phone sensors in order to design a context aware reminder system to assist cognitive impaired people. Objectives: Different reminder systems, needs for such systems, technologies and models used to build a reminder system are identified in this research work. Ultimate goal of the study is to assist cognitive people in their daily life activities, using available embedded technologies of smart phones. Following objectives were set to achieve the goal of the thesis work: • What are reminder systems and why do we need such systems? • What are the different kinds of technologies reported in literature for reminder systems? • What are the issues encountered by cognitive impaired/elderly people while performing their daily life activities? • How to design and implement context aware reminder system using Smartphone embedded sensors? Methods: Mix method approach is used to carry out this study. Literature review is conducted based on the notion of systematic review. Data is collected through survey and interviews, conducted in south Sweden municipality, to analyze and indentify daily life issues and problems of cognitive people. Experiments are performed in real environment to test and verify our application. We evaluate the performance of activity recognition algorithm, implemented in the application, using Weka. Results: Various reminder systems, their needs and underlined technologies are identified and reported. Activities of daily living and issues addressed by these reminder systems are also identified. Survey and interviews help us to identify issues and problems faced by cognitive impaired/elderly while performing their daily life activities. For example, we find out that cognitive people not only forget their daily life activities but also during performing these activities. Conclusions: Many proposed models in literature are related to each other and use similar sensor based data from various technologies. Based on literature review, survey and interviews we have concluded that context based reminder system is essential for cognitive disabled people. It leads us to design a context based reminder system for android based smart phones. The preliminary tests help us to verify our model but there is absolute need for further empirical verification and validation.
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Karlaputi, Sarada. "Evaluating the Feasibility of Accelerometers in Hand Gestures Recognition." Thesis, University of North Texas, 2014. https://digital.library.unt.edu/ark:/67531/metadc699862/.
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Gesture recognition plays an important role in human computer Interaction for intelligent computing. Major applications like Gaming, Robotics and Automated Homes uses gesture recognition techniques which diminishes the usage of mechanical devices. The main goal of my thesis is to interpret SWAT team gestures using different types of sensors. Accelerometer and flex sensors were explored extensively to build a prototype for soldiers to communicate in the absence of line of sight. Arm movements were recognized by flex sensors and motion gestures by Accelerometers. Accelerometers are used to measure acceleration in respect to movement of the sensor in 3D. Flex sensors changes its resistance based on the amount of bend in the sensor. SVM is the classification algorithm used for classification of the samples. LIBSVM (Library for Support Vector Machines) is integrated software for support vector classification, regression and distribution estimation which supports multi class classification. Sensors data is connected to the WI micro dig to digitize the signal and to transmit it wirelessly to the computing device. Feature extraction and Signal windowing were the two major factors which contribute for the accuracy of the system. Mean Average value and Standard Deviation are the two features considered for accelerometer sensor data classification and Standard deviation is used for the flex sensor analysis for optimum results. Filtering of the signal is done by identifying the different states of signals which are continuously sampled.
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Tingle, Mark E. "Performance evaluation of a prototyped wireless ground sensor networks." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2005. http://library.nps.navy.mil/uhtbin/hyperion/05Mar%5FTingle.pdf.
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Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, March 2005.<br>Thesis Advisor(s): Murali Tummala, Hersch Loomis. Includes bibliographical references (p. 87-91). Also available online.
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Shaltis, Phillip Andrew. "A wearable blood pressure sensor using oscillometric photoplethysmography and micro accelerometers." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/40363.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.<br>Includes bibliographical references (leaves 119-124).<br>Monitoring arterial blood pressure (ABP) with a sensor virtually imperceptible to the wearer, for continuous periods of weeks, months, or years, could prove revolutionary in the diagnosis and treatment of chronic hypertension and heart failure, as well as a monitoring tool for convalescing individuals, and individuals in hazardous duty (such as firefighters or soldiers). To this end, a miniaturizable, non-invasive blood pressure sensor is designed and validated. A solid, coin-sized cuff-less photoplethysmography (PPG) sensor worn over a palpable artery is utilized to measure arterial blood pressure. Measurements are obtained through a modified oscillometric technique which eliminates the need for a high pressure cuff and instead, takes advantage of natural hydrostatic pressure changes caused by raising and lowering the subject's arm. In this work, the principle of hydrostatic oscillometry is first detailed. To better understand the internal mechanisms of pressure propagation within the tissue, a comprehensive non-linear finite element model of the finger base is constructed and validated using a combination of magnetic resonance imaging and experimental tissue stiffness measurements.<br>(cont.) A prototype finger blood pressure monitor is designed and constructed in combination with a novel accelerometer-based height sensor. The 95% confidence interval for a Bland-Altman comparison between the proposed sensor's mean arterial pressure (MAP) measurements and the simultaneous Finapres MAP measurements is [+919, -283] Pa ([+6.91, -9.04] mmHg). The percent difference between the two methods is shown to be 3.0%. A method for continuous MAP measurements utilizing the sensor system is proposed and is shown to be capable of providing reliable measurements for several minutes.<br>by Phillip Andrew Shaltis.<br>Ph.D.
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Durango, Melisa de Jesus Barrera. "SIRAH : sistema de reconhecimento de atividades humanas e avaliação do equilibrio postural /." Ilha Solteira, 2017. http://hdl.handle.net/11449/151317.
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Orientador: Alexandre César Rodrigues da Silva<br>Resumo: O reconhecimento de atividades humanas abrange diversas técnicas de classificação que permitem identificar padrões específicos do comportamento humano no momento da ocorrência. A identificação é realizada analisando dados gerados por diversos sensores corporais, entre os quais destaca-se o acelerômetro, pois responde tanto à frequência como à intensidade dos movimentos. A identificação de atividades é uma área bastante explorada. Porém, existem desafios que necessitam ser superados, podendo-se mencionar a necessidade de sistemas leves, de fácil uso e aceitação por parte dos usuários e que cumpram com requerimentos de consumo de energia e de processamento de grandes quantidades de dados. Neste trabalho apresenta-se o desenvolvimento do Sistema de Reconhecimento de atividades Humanas e Avaliação do Equilíbrio Postural, denominado SIRAH. O sistema está baseado no uso de um acelerômetro localizado na cintura do usuário. As duas fases do reconhecimento de atividades são apresentadas, fase Offline e fase Online. A fase Offline trata do treinamento de uma rede neural artificial do tipo perceptron de três camadas. No treinamento foram avaliados três estudos de caso com conjuntos de atributos diferentes, visando medir o desempenho do classificador na diferenciação de 3 posturas e 4 atividades. No primeiro caso o treinamento foi realizado com 15 atributos, gerados no domínio do tempo, com os que a rede neural artificial alcançou uma precisão de 94,40%. No segundo caso foram gerados 34 ... (Resumo completo, clicar acesso eletrônico abaixo)<br>Doutor
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Bales, Dustin Bennett. "Characteristic Classification of Walkers via Underfloor Accelerometer Gait Measurements through Machine Learning." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/81183.
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The ability to classify occupants in a building has far-reaching applications in security, monitoring human health, and managing energy resources effectively. In this work, gender and weight of walkers are classified via machine learning or pattern recognition techniques. Accelerometers mounted beneath the floor of Virginia Tech's Goodwin Hall measured walkers' gait. These acceleration measurements serve as the inputs to machine learning techniques allowing for classification. For this work, the gait of fifteen individual walkers was recorded via fourteen accelerometers as they, alone, walked down the instrumented hallway, in multiple trials. These machine learning algorithms produce an 88 % accurate model for gender classification. The machine learning algorithms included are Bagged Decision Trees, Boosted Decision Trees, Support Vector Machines (SVMs), and Neural Networks. Data reduction techniques achieve a higher gender classification accuracy of 93 % and classify weight with 64% accuracy. The data reduction techniques are Discrete Empirical Interpolation Method (DEIM), Q-DEIM, and Projection Coefficients. A two-part methodology is proposed to implement the approach completed in this thesis work. The first step validates the algorithm design choices, i.e. using bagged or boosted decision trees for classification. The second step reduces the walking data measured to truncate accelerometers which do not aid in increasing characteristic classification.<br>Master of Science
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BERGLIND, NICLAS. "State estimation of motorcycle fork : A Kalman filter, accelerometer and pressure sensor approach." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-142440.
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A concept for estimation of the states of a motorcycle front fork, stroke and stroke speed, have been developed utilizing a Kalman filter, pressure sensor and accelerometers. The concept development involved sensor and suspension system modeling, Kalman filter setup and tuning, sensor mounting and sensor bracket fabrication, and data recording in a dynamometer and on the road. The result shows a stroke estimation error of about ±smm when one absolute reference position is known. Difficulties arise when the temperature affect the pressure and makes the stroke estimate drift. Two solutions are proposed, one involving estimation of temperatures and compensating the drifting stroke estimate. The other solution is based on a calibration algorithm that can calibrate the system when the motorcycle is on the road. Such a calibration algorithm is proven to work according to a patent [1] and would also benefit from calibrating other sources of errors such as for example changing oil level. Two additional solutions are also investigated, namely using only accelerometers for stroke speed estimation or using accelerometers and a binary sensor that sends a pulse as the stroke reaches a certain value. Using accelerometers require double integration of the accelerometer measurements in order to obtain a value of the stroke. The integration will sum the offset in the accelerometer measurement (there will always be a small offset in a sensor) which will then will drift if no complementary sensor is used to compensate for drift. Due to that the estimation result is only useful for less than a second.<br>Ett koncept för estimering av en motorcykelframgaffels tillstånd, slag och slaghastighet, har utvecklats med hjälp av ett kalmanfilter, trycksensor och accelerometrar. onceptutvecklingen innefattade modellering av sensor och stötdämparsystem, installation och parameterinställning av Kalmanfilter, sensormontering och tillverkning av sensorfästen, och datainspelning i dynamometer och påvägen.Resultat visar ett estimerings fel i slag på ca ±smm när en absolut referensposition är känd. Svårigheter uppkommer dåtemperaturen påverkar trycket och gör att slagestimeringen driver. Tvålösningar föreslås, en innefattar estimering av temperaturer och kompensering för drivande slagestimering. Den andra lösningen använder en kalibreringsalgoritm som kan kalibrera systemet medan motorcykeln körs på vägen. Det är bevisat att en sådan kalibreringsalgoritm fungerar av ett patent [1] som också har fördelen att kalibrera andra felkällor som till exempel ändrad oljenivå. Två alternativa lösningar har också utretts, nämnligen att använda endast accelerometrar till slaghastighetsestimering eller att använda accelerometrar och en binärsensor som skickar en puls när ett visst ställe i slaget nås. För att använda accelerometrar krävs en dubbel integration av accelerometermätvärden för att erhålla ett värde i slag. Integrationen kommer summera accelerometerns mätvärdesoffset (det finns alltid en liten offset i en sensor) som medför att estimeringen driver om inte en kompletterande sensor används för att kompensera drift. På grund av detta är estimeringsresultatet endast användbart i minde än en sekund.
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Stuart-Watson, David. "A simple force feedback accelerometer/seismometer based on a tuning fork displacement sensor." Master's thesis, University of Cape Town, 2005. http://hdl.handle.net/11427/5098.
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Includes bibliographical references (p. 189-194).<br>This thesis describes research into the use of a piezoelectric tuning fork as the displacement sensor in a simple force feedback seismometer. The research also includes the use of a second piezoelectric transducer as both the suspension system and the force transducer for the seismometer. A simple inertial seismometer model, based on a damped mass-spring system, was developed.
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Abyarjoo, Fatemeh. "Sensor Fusion for Effective Hand Motion Detection." FIU Digital Commons, 2015. http://digitalcommons.fiu.edu/etd/2215.
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Mihaľko, Juraj. "MEMS inerciální snímače." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2012. http://www.nusl.cz/ntk/nusl-219724.
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The aim of this master’s thesis is to describe the basic measurement methods of micro-electromechanical inertial sensor, their physical principles and errors. Measurement of inertial sensors is very important for the parameterization of their errors and their subsequent mathematical model by which it is possible to minimize the measurement error impact on inertial navigation. The practical part is dedicated to create automated measurement setup for measurement stability of the offset. Hardware and software from National Instruments is used in measurement chain. The work is next focused on measuring seven inertial sensors based on three different physical principles. In addition to creating measurement setup, we also defined three inertial sensor parameters, describing theoretical behavior of the sensor output.